BCG vaccine is used to prevent: MCQ with Answer and Explanation

Explanation:
The limbic system is a complex set of structures in the medial temporal lobe, including the hippocampus, amygdala, and hypothalamus. It is often called the 'emotional brain' and is primarily responsible for processing emotions (fear, anger, pleasure), forming and retrieving memories, and regulating motivation and homeostatic drives (hunger, thirst). The medulla regulates heart rate, the cerebellum coordinates movement, and the occipital/temporal lobes process sensory information.

Explanation:
Folic acid prevents neural tube defects like spina bifida. It is recommended during early pregnancy. B₁₂ is for DNA synthesis, D for bone, K for clotting.

Explanation:
The Sinoatrial (SA) node, located in the right atrium, is the natural pacemaker because its cells are autorhythmic; they can spontaneously generate action potentials without external neural input. Crucially, the SA node has the highest intrinsic rate of depolarization (about 70-80 beats per minute) compared to other autorhythmic tissues like the AV node or Purkinje fibers. Therefore, it sets the pace for the entire heart, overriding slower pacemakers.